Bussmann 4A Fast Acting Glass Fuse with 250VAC Voltage Rating; S500 Series

These cartridge-style, fast-acting glass fuses open within seconds of being exposed to overloads and short circuits. They're commonly used in instrument panels, small appliance circuits, and automotive accessories. Also called fast-blow glass fuses, they are highly sensitive to changes in current flow and don't tolerate temporary overload currents or power surges.

Glass fuses provide overcurrent protection for low-current circuits in appliances, electronics circuit boards, and lighting fixtures. They typically have a voltage rating of 300VAC or less and are used for applications where they won't be exposed to high heat that could shatter the glass. Their small, cylindrical body is see-through for checking whether the fuse wire is intact or has melted.